Living Environment Regents Practice Test

What role does the placenta play in fetal development?

1. Provides a physical barrier to all pathogens

2. Supplies oxygen and nutrients

3. Functions as the primary site for cell division

4. Acts as a waste disposal system

The correct answer is: Supplies oxygen and nutrients

The placenta is a vital organ that forms during pregnancy, serving several key functions essential for fetal development. Its primary role is to supply oxygen and nutrients to the developing fetus, which are critical for growth and proper organ function. The placenta achieves this through a complex exchange mechanism between maternal blood and fetal blood, allowing for the transfer of essential substances while keeping the two blood supplies separate. This ensures that the fetus receives the necessary building blocks for development without directly mixing maternal and fetal blood, which could lead to complications. In addition to supplying nutrients, the placenta also supports the transport of waste products from the fetus back into the mother's circulation for elimination, but its most crucial function remains the provision of oxygen and nutrients, which directly influence the health and growth of the fetus throughout gestation.